This invention relates to pressure welding of metal workpieces and, more particularly, is directed to a method and apparatus for pressure welding metal workpieces of high strength aluminum or magnesium alloy and to novel workpieces welded thereby.
The pressure welding of metals by cold welding and hot welding techniques is well known. Each technique has certain limitations in that cold pressure welding requires a large amount of deformation and extremely high pressures to obtain a weld and, in many cases, it has been found impossible to obtain welds at room temperature because of excessive cracking and insufficient flow of the metal. Hot pressure welding of metals such as aluminum, on the other hand, normally is conducted at a temperature in excess of 900.degree. F. with relatively little deformation and upset. However, known hot pressure welding methods have the inherent disadvantage of overaging, recrystallizing and annealing the metals welded resulting in low joint efficiencies of about 30 to 40%.